Can limits for Equivalence TOST use ratios instead of differences between the test and reference groups?

Question

Minitab allows the lower and upper equivalence limits for TOST to be set as differences (either balanced or unbalanced, e.g. -123 and +345) or as ratios (either balanced or unbalanced, e.g. 0.8 and 1.2 if you wanted an equivalence margin of +/- 20%).

I don't see this option for JMP and wondered if it was available and how to access it.

Thanks.

Mark_Bailey · Answer

I wonder if you are asking about counts and rates. JMP 17 added equivalence tests for risk difference and relative risk based on rates derived from counts. That might suit your data. I am not sure.

derchieh · Answer

The Distribution Platform => Test Equivalence is only applicable if the ratio of interest is derived from paired data. For example,

Then one can do equivalence test on the ratio using Distribution Platform => Test Equivalence, where ratio (A/B) is the Y.

I am not aware JMP 16 can do equivalence test for ratios directly if the ratio is derived from unpaired variables. There are other ways around it, eg. by log transformation, but it isn't always appropriate. If I am wrong, please let me know! Thanks!

LeeLandeen · Answer

Thanks for the suggestion!